Manufacture of cyclopentadienyl manganese tricarbonyl compounds



MANUFACTURE OF CYCLOPENTADIENYL MAN- GANESE TRICARBONYL COMPOUNDS Hoyt J. Cragg, Baton Rouge, La., assignor to Ethyl Corporation, New York, N. Y., a corporation of Delaware No Drawing. Application July 24, 1957 Serial No. 673,765

2 Claims. (Cl. 202-46) This invention relates to. the manufacture of organo "'metal carbonyl compounds and more particularly to the separation and recovery of cyclopentadienyl manganese tricarbonyl compounds, and especially alkylcyclopentadienyl manganese tricarbonyls.

' Cyclopentadienyl manganese tricarbonyl compounds have been found to be exceptionally effective an-tiknocks for use in fuel, for spark plug'ignition internal combuspreciable'deposits on the engine piston, valves and spark plug surfaces and likewise are not abrasive to the engine parts as are characteristic of iron compounds.

A preferred method of manufacture of these cycloreacting carbon monoxide with a bis-(cyclopentadienyl) manganese compound, e. g. bis-(methylcyclopentadienyl) manganese. In this reaction, only one of the two cyclopentadienyl radicals in the bis-compound is used in forming the product. The othercyclopentadienyl radical is lost as byproduct, normally polymerizing to .a soft, sticky material. This byproduct causes difficulty in subsequent recovery of the cyclopentadienyl manganese tricarbonyl as hereinafter described.

The bis(cyclopentadienyl)manganese compound is normallymade by--reaction of a cyclopentadienyl]sodium compound or other alkalimetal compound with a manganous chloride or other salt. Sodium chloride is formed as a byproduct, two moles per mole of the bis-manganese product. The carbon monoxide is normally added directly to this reaction product, forming a second product containing the desired cyclopentadienyl manganese tricarbonyl but also containing, frequently as the major constituent, impurities including the polymer, sodium salts, unreacted manganese salts and the like. These impurities interfere with complete recovery, e. g. distillation, of the desired product and, in addition, are extremely difficult to discharge from a steam still or other recovery equipment.

:It is accordingly an object of this invention to provide an improved method for manufacture of cyclopentadienyl manganesetricarbonyl compounds. Another object is to provide; an improved method for the recovery and separation of'these compounds from a reaction product convtaining inorganic and polymeric impurities. A more specific object is to provide a simple and convenient United States Patent ally, when used alone, result in the formation of an emulpentadienyl manganese tricarbonyl compounds comprises objects and advantages of this invention will be apparent from the following description and appended claims.

It has now been found that the alkali metal salts selected from the group consisting of silicates, phosphates, borates and carbonates, when used in relatively low concentrations, have unexpected activity as steam distillation aids and are highly effective in maintaining the impurities in finely divided form such that essentially all of the desired cyclopentadienyl manganese tricarbonyl compound can be recovered from the crude reaction mass and such that the residue can be easily and completely discharged from the separation equipment as a fluid, easily handled slurry. It has further been found that dispersing agents, particularly of theanionic type, additionally aid in efficient separation of the desired product while maintaining the residue in a fluid dischargeable state. Thus, the product can be recovered using steam distillation, without the many problems of agglomeration, low efliciency, etc.,

while at the same time obtaining the inherent advantages of excellent heat transfer, low temperature operation, rapid separation and an easily handled residue slurry.

The function of these alkali metal salts in improving product separation and maintaining the residue in a finely divided condition is not completely understood. However, it is known that the function is peculiar to these salts. Many somewhat similar materialsare completely ineffective for this purpose.

Thus, soaps and detergents are not equivalents to these alkali metal salts but, actusion which is extremely difficult to process, Likewise,

inorganic and organic acids, e. g. phosphoric or oleic acids, do not prevent agglomeration of the product residue. sequestering agents, in general, are not suitable for this invention. Also, other inorganic salts, such as sodium chloride are similarly ineffective.

More specifically, a preferred process of this invention comprises an initial distillation, either vacuum or under pressure, to remove the solvent from the crude reaction mass. The solvent-free reaction mass is then dispersed in water, containing from 1 to 10 percent of a steam distillation aid, as defined above, and thereafter steam distilled to separately recover the product. The impurities remain suspended in the aqueous phase. When solvents are used which have a boiling point higher than the cyclepentadienyl manganese tricarbonyl product, solvent distillation follows the steamdistillation.

- The following are typicalexamples of the present invention for the purpose of illustrating the beneficial characteristics of this invention. All units in the following examples are given in parts by weight.

EXAMPLE I A crude reaction product (IOOparts) containing about equal quantities of methylcyclopentadienyl manganese'tripressure of the'system'was reduced to 'abou't 2'to5 mni.

of mercury. Under these conditions, about 30 parts of solvent were recovered having a purity of about 95' percent. The solvent-free residue was then dispersed in an equal volume of water containing about 1 part of sodium metaphosphate (3 percent based on the weight of methylcyclopentadienyl manganese tricarbonyl). Thereafter, the solvent-free residue: was steam distilled using 40 p. s. i. g. steam and the temperature of the overhead was increased to between 100 to 105 C. at atmospheric pressure. The methylcyclopentadienyl manganese tricarbonyl product was'removed from the reaction mass as a water azeotrope and, upon separation of phases, about 34 parts of product were obtained. The distillation residue, consisting primarily of metal salts and polymeric materials,v was finely divided and was readily discharged from the distillation equipment as a highly fluid aqueous slurry.

The crude reaction product used in this example was prepared by reacting 3.36 parts of sodium metal with 14.26 parts of rnethylcyclopentadiene in 9.5 parts of diethylene glycol dirnethyl ether at a temperature of 110 C. After approximately one hour of agitation at this temperature, 9.15 parts of manganous chloride were added to the reaction mass and this mixture was thereafter agitated for approximately 1 /2 hours at 125 C. The reaction product was thereafter transferred to a pressure vessel wherein it was subjected to carbon monoxide pressure (500 p. s. i.) and this reaction mixture was vigorously agitated at 190 C. until the reaction was essentially complete. This crude reaction product, protected against exposure to air or moisture, was thereafter treated in accordance with the above procedure to recover the desired rnethylcyclopentadienyl manganese tricarbonyl.

The manganese compound prepared as above is then subjected to fractionation and this purified product is thereafter blended with gasoline. The following Table I presents data showing the octane increase of a commercial gasoline having an initial boiling point of 94 F. and a final boiling point of 390 F. The antiknock value of the fuel as determined by the ratings are given in octane numbers for figures below 100 and in Army-Navy performance numbers for values above 100. The method of determining performance numbers is explained in the booklet Aviation Fuels and Their Effect on Engine Performance, NAVAER-06-5-501, USAF T. O. No. 06-554, published in 1951.

Example I was repeated in a series of runs except that .no distillation aid was employed during the steam distillation. The solids agglomerated during the distillationsuch that only 60-80 percent of the product could be recovered. The distillate bottoms were large agglomerated masses which tenaciously stuck and were bonded to the vessel and had to be removed by scraping manually from the vessel walls. The material resembles an asphalt, varying from a tough pliable material to a hard brittle material in the several runs.

EXAMPLE III Example I was repeated except that sodium silicate (Na SiO' .9H O) was employed as the distillation aid. As in Example I, essentially complete recovery of the methylcyclopentadienyl product was obtained and there was noagglomeration or sticking of the distillate bottoms to the vessel walls. Instead, a finely divided slurry was discharged from" the" distillation still;

EXAMPLE IV Example I is repeated except that a composition containing about 28.8% trisodium phosphate, dodecahydrate, 34.8% tetrasodium pyrophosphate, 30.1% sodium metasilicate, pentahydrate, 2.2% sodium carbonate and 4.1% sodium stearate was employed as the distillation aid instead of' the sodium metaphosphate. In this example, 5 parts of the. distillation aid was employed for 321 parts of crude reaction mass (approximately 4% by weight, based on the weight of the rnethylcyclopentadienyl manganese tricarbonyl). The slurry obtained in this example was readily discharged from the steam still and could be easily handled byconventional process equipment.

EXAMPLE V Example IV was repeated except that only 2.5 parts of the distillation aid was employed. Only a minor amount of agglomeration was obtained with this lower concentration.

EXAMPLE VI Example IV was repeated except that 10 parts of the distillation aid were employed with similar results. The distillation bottoms were not agglomerated and could be discharged from the steam still as a fine water slurry.

EXAMPLE VII ExampleI was repeated except that 5 parts of sodium carbonate (Na CO was employed with about 300 parts of crude reaction mass (about 4% based on the weight of methylcyclopentadienyl manganese tricarbonyl). No agglomeration of the distillation residue was encountered and the residue was readily slurried and discharged from the steam still.

EXAMPLE VIII Example VII was repeated except that borax was employed and similar results were obtained.

EXAMPLE IX Example VII was repeated except that 5 parts of sodium metasilicate was used with /2 part of Tide (a commercial detergent marketed by Proctor and Gamble).

EXAMPLE X Example IX was repeated except that white soapwas used in place of the Tide. No agglomeration of the product residue was I encountered.

EXAMPLE PG Example VII was repeated except that 5parts of sodium metaphosphate was used with /2 part of the sodium salt of oleic acid. Equally good results were obtained.

EXAMPLE XII Example I is repeated except that the crude reaction mass contained cyclopentadienyl manganese tricarbonyl, instead of the methyl substituted derivative. This crude reaction mass was prepared similarly to the product of Example I except that cyclopentadiene was employed instead of the methylcyclopentadiene.

EXAMPLE XIII Example I is repeated except that the. crude reaction product contained indenyl manganese tricarbonyl instead of methylcyclopentadienyl manganese tricarbonyl. Similar results were obtained.

Thefollowing Table. 11 illustrates other embodiments of the present invention. In all instances, serious agglomeration ofthe reaction mass is avoided and the distillation residue can be: readily slurried and discharged from the steam still;

Table II Crude Reaction Mass Distillation Aid Inorg. Wt. Wt. Product Solvent Salt Metal Salt Per- Dispersant Per- 1 cent 1 cent 1 tetrahydrofuran LiCl NaiPzoa 2. dlethylene glycol dibutyl ether. K01 NaiPgoa 4. O sulfonated castor oil... 0. benzene-.. N 2.01 N21200:; 3.0 Ammonium ricmoleate... 0.7 toluene NaCl KP03 3. 0 lauryl alcohol sulfonate.... 0.2 diethylene glycol diethyl ether. KCl LIP O 3. 5 fatty amide sulfonate 0. 9 tetraethylene glycol dimethyl NaGl K O 2. 5 sodium salt of butyl 1. 5

ether. rieinoleate. cyclohexylamine NaOl Nag]? O4 4. 0 stearo glycerol sulfate.... 0. 6 diethylene glycol dimethyl N 9.01 NaPOi 2. 8 sodium alkyl naphthalene 4. 0

ether. sulfonate (Alkoterge). .do N aOl Na? 03 3. 0 sulfonation product of wax 1. 2

residues. MMT... do. NaOl N aPOa 4. 5 sodium ligno sult'onate... 1. 0

1 Based on the Weight of cyclopentadienyl manganese trllcarbonyl product.

MMT-methylcyclopentadlenyl manganese trlcarbony GMT-cyclopentadienyl manganese tricarbonyl. EMT-ethylcyclopentadienyl manganese tricarbonyl. IMT-indenyl manganese tricarbonyl.

The present process is suitable for recovery of a wide variety of cyclopentadienyl manganese tricarbonyl compounds and is particularly desirable for recovery of such compounds having cyclopentadienyl radicals containing from 5 to 13 carbon atoms. These latter compounds have molecular weights up to about 315. Typical examples of cyclopentadienyl manganese tricarbonyl compounds which can be recovered in accordance with this invention are cyclopentadienyl manganese tricarbonyl, methylcyclopentadienyl manganese tricarbonyl, idenyl manganese tricarbonyl, ethyl cyclopentadienyl manganese tricarbonyl, n-octyl cyclopentadienyl manganese tricarbonyl, phenyl methylcyclopentadienyl manganese tricarbonyl and the like.

The above cyclopentadienyl manganese tricarbonyl compounds can be prepared from corresponding bis(cy clopentadienyl) alkali metal compounds by reaction with carbon monoxide. For example, cyclopentadienyl manganese tricarbonyl is prepared by the reaction of carbon monoxide with bis(cyclopentadienyl) manganese. Likewise, methylcyclopentadienyl manganese tricarbonyl is prepared by reacting carbon monoxide with bis(methylcyclopentadienyl) manganese. Thus, corresponding cyclopentadienyl manganese tricarbonyl compounds can be prepared from bis(ethyl cyclopentadienyl) manganese, bis(n-octyl cyclopentadienyl) manganese, 'bis(indenyl) manganese, bis(fluorenyl) manganese and the like.

The distillation aids suitable for this invention, as noted above, can be selected from the group consisting of alkali metal phosphates, silicates, carbonates and borates. Typical examples of suitable distillation aids are sodium, potassium and lithium metaphosphates, trisodium-, tripotassiumand trilithiumphosphates, the alkali metal pyrophosphates, such as tetrasodium pyrophosphate, sodium hexametaphosphate, sodium tripolyphosphate, the alkali metal metasilicates, such as sodium and potassium metasilicates, the alkali metal orthoand metasilicates, e. g. sodium orthosilicate and sodium metasilicate pentahydrate, the sesquisilicates, sodium and lithium metaborate, the polyborates, and the alkali metal vtetraborates, such as borax.

The above distillation aids can be used in concentrations from about 1 to 10 percent, although a more preferred range is from 2 to 5 percent based upon the weight of the cyclopentadienyl manganese tricarbonyl compound in the crude reaction product. Lower concentrations can sometimes be employed although the results become somewhat inconsistent at the lower concentrations. Higher concentrations than 10 percent, while giving satisfactory operation, are usually unnecessary and uneconomic.

The dispersing agents which are suitable in combination with the distillation aids are preferably of the anionic type and include soaps, and other products derived from the saponi'fication of fats, products obtained by direct sulfonation of fatty matter, products obtained by sulfonation of fatty esters, sulfonated aromatic hydrocarbons, sulfonated or chlorosulfonated paraflin hydrocarbons and sulfamides and sulfimides derived from paraflinic hydrocarbons. Typical examples of suitable dispersing agents are soaps derived from oleic acid, caster oil, coconut oil; sulfonated glycerides and their fatty acids; sulfonated acids, such as oleic, linoleic and linolenic acids; sulfonated castor oil, sulfonated products of esterified castor oil e. g. with butyl alcohol; sulfonated derivatives of fatty acids, mono-glycerides and mono-glycolides, sodium alpha naphthalene monosulfonate, sodium tetrahydronaphthalene sulfonate, alkyl aryl sulfonates, such as sodium dodecyl benzene sulfonate, the alkali metal salts of octyldecylmethyl sulfamide; sodium lignosulfonate and the like. Many other examples of suitable dispersing agents are given in Encyclopedia of Surface Active Agents, Sisley and Wood, Chem. Publ. Co., N. Y. (1952).

The concentration of dispersing agent employed can range from about 0.01 to 10 percent based upon the weight of the cyclopentadienyl manganese tricarbonyl compound in the crude reaction mixture. A more preferred concentration is from 1 to 5 percent. Greater quantities than these sometime results in emulsification, although the presence of the phosphates, silicates, borates and carbonates reduces this tendency. In fact, in the absence of the latter compounds, small quantities of the dispersing agent will normally result in emulsification, such as to make the distillation of the desired product almost impossible.

The steam distillation can be carried out over a wide range of temperature and pressures and depends to a large extent on the cyclopentadienyl manganese tricarbonyl compound being distilled. The temperature of the distillation is usually the azeotropic temperature of the particular productand steam under the particular pressure conditions employed, normally from about 0 to C. Usually the distillation is conducted at essentially atmospheric although pressures from sub-atmospheric up to about 1'0 atmospheres or higher can be employed.

The crude reaction product should be protected from contact with air or moisture since materially greater difficulty is encountered in the distillation after prolonged exposure to either air or moisture. Normally, the reaction product is maintained under a inert atmosphere prior to distillation or the crude reaction mixture is fed directly to the distillation equipment in a closed system.

The above cyclopentadienyl manganese tricarbonyl compounds can be prepared by a number of processes and, in general, are synthesized in three separate steps. An alkali metal (e. g. sodium, potassium or lithium) cyclopentadienyl compound is prepared by reaction of the corresponding alkali metal with the cyclopentadiene hydrocarbon in a suitable solvent, such as a hydrocarbon or ether, e. g. toluene, diethylene glycol diiri'c'thyl ether or tetrahydrofuran. This reaction is conducted with agi"-' tation at a temperature of from Ot'o 250 C. preferably above 100 C., using either the cyclopentadiene monomer or dimer. Other suitable methods are disclosed in British 763,047 and U. S. 2,777,887. This'r'eaction mixture is then reacted with a manganous salt. Suitable manganous salts are halides, such as the chlorideor a bromide, manganous sulfate or organic salts, such as the acetate. In general, this reaction is conducted in ether type solvents, such as those discussed above, at a temperature of 100 to 250 C., usually from 130 to 175 C. This second retraction product is then reacted with carbon monoxide usually at pressures of from 1-00 to 500 lbs./ sq. in., although both lower and higher pressures can be used. This carbonylation reaction is normally conducted at temperatures of from 150 to 250 C. using agitation.

I claim:

1. In aprocess for producing cyclopentadienyl manganese tricarbonyl' compounds in which" a cyclopentadiene compound is reacted with an alkali 'metal, the reaction product is' thereafter reacted Witha -manganous salt and the product of the latter reaction is then reacted with carbon monoxide, in the presence of a solvent, the improvernent comprising steam distilling said cyclopentadienyl manganese tricarbonyl compound in the presence of from about l-lO percent by Weight, based on the Weight of said tricarbonyl compound, of a distillation aid selected from the group consisting of alkali metal phosphates, silicates, carbonates and borates.

2. The process of claim 1 wherein the steam distillation is conducted inth'e additional presence of from about 0.1 to 10 percent of a dispersingagent.

No references cited. 

1. IN A PROCESS FOR PRODUCING CYCLOPENTADIENYL MANGANESE TRICARBONYL COMPOUNDS IN WHICH A CYCLOPENTADIENE COMPOUND IS REACTED WITH AN ALKALI METAL, THE REACTION PRODUCT IS THEREAFTER REACTED WITH A MANGANOUS SALT AND THE PRODUCT OF THE LATTER REACTION IS THEN REACTED WITH CARBON MONOXIDE, IN THE PRESENCE OF A SOLVENT, THE IMPROVEMENT COMPRISING STEAM DISTILLING SAID CYCLOPENTADIENYL MANGANESE TRICARBONYL COMPOUND IN THE PRESENCE OF FROM ABOUT 1-10 PERCENT BY WEIGHT, BASED ON THE WEIGHT OF SAID TRICARBONYL COMPOUND, OF A DISTILLATION AID SELECTED FROM THE GROUP CONSISTING OF ALKALI METAL PHOSPHATES, SILICATES, CARBONATES AND BORATES. 